/*! FileSaver.js
 *  A saveAs() FileSaver implementation.
 *  2014-01-24
 *
 *  By Eli Grey, http://eligrey.com
 *  License: X11/MIT
 *    See LICENSE.md
 */

/*global self */
/*jslint bitwise: true, indent: 4, laxbreak: true, laxcomma: true, smarttabs: true, plusplus: true */

/*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */

(function() {
    var saveAs = saveAs
        // IE 10+ (native saveAs)
        || (typeof navigator !== "undefined" &&
            navigator.msSaveOrOpenBlob && navigator.msSaveOrOpenBlob.bind(navigator))
        // Everyone else
        || (function(view) {
            "use strict";
            // IE <10 is explicitly unsupported
            if (typeof navigator !== "undefined" &&
                /MSIE [1-9]\./.test(navigator.userAgent)) {
                return;
            }
            var
                doc = view.document
                // only get URL when necessary in case BlobBuilder.js hasn't overridden it yet
                , get_URL = function() {
                    return view.URL || view.webkitURL || view;
                }
                , URL = view.URL || view.webkitURL || view
                , save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a")
                , can_use_save_link = !view.externalHost && "download" in save_link
                , click = function(node) {
                    var event = doc.createEvent("MouseEvents");
                    event.initMouseEvent(
                        "click", true, false, view, 0, 0, 0, 0, 0
                        , false, false, false, false, 0, null
                    );
                    node.dispatchEvent(event);
                }
                , webkit_req_fs = view.webkitRequestFileSystem
                , req_fs = view.requestFileSystem || webkit_req_fs || view.mozRequestFileSystem
                , throw_outside = function(ex) {
                    (view.setImmediate || view.setTimeout)(function() {
                        throw ex;
                    }, 0);
                }
                , force_saveable_type = "application/octet-stream"
                , fs_min_size = 0
                , deletion_queue = []
                , process_deletion_queue = function() {
                    var i = deletion_queue.length;
                    while (i--) {
                        var file = deletion_queue[i];
                        if (typeof file === "string") { // file is an object URL
                            URL.revokeObjectURL(file);
                        } else { // file is a File
                            file.remove();
                        }
                    }
                    deletion_queue.length = 0; // clear queue
                }
                , dispatch = function(filesaver, event_types, event) {
                    event_types = [].concat(event_types);
                    var i = event_types.length;
                    while (i--) {
                        var listener = filesaver["on" + event_types[i]];
                        if (typeof listener === "function") {
                            try {
                                listener.call(filesaver, event || filesaver);
                            } catch (ex) {
                                throw_outside(ex);
                            }
                        }
                    }
                }
                , FileSaver = function(blob, name) {
                    // First try a.download, then web filesystem, then object URLs
                    var
                        filesaver = this
                        , type = blob.type
                        , blob_changed = false
                        , object_url
                        , target_view
                        , get_object_url = function() {
                            var object_url = get_URL().createObjectURL(blob);
                            deletion_queue.push(object_url);
                            return object_url;
                        }
                        , dispatch_all = function() {
                            dispatch(filesaver, "writestart progress write writeend".split(" "));
                        }
                        // on any filesys errors revert to saving with object URLs
                        , fs_error = function() {
                            // don't create more object URLs than needed
                            if (blob_changed || !object_url) {
                                object_url = get_object_url(blob);
                            }
                            if (target_view) {
                                target_view.location.href = object_url;
                            } else {
                                window.open(object_url, "_blank");
                            }
                            filesaver.readyState = filesaver.DONE;
                            dispatch_all();
                        }
                        , abortable = function(func) {
                            return function() {
                                if (filesaver.readyState !== filesaver.DONE) {
                                    return func.apply(this, arguments);
                                }
                            };
                        }
                        , create_if_not_found = {create: true, exclusive: false}
                        , slice
                    ;
                    filesaver.readyState = filesaver.INIT;
                    if (!name) {
                        name = "download";
                    }
                    if (can_use_save_link) {
                        object_url = get_object_url(blob);
                        // FF for Android has a nasty garbage collection mechanism
                        // that turns all objects that are not pure javascript into 'deadObject'
                        // this means `doc` and `save_link` are unusable and need to be recreated
                        // `view` is usable though:
                        doc = view.document;
                        save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a");
                        save_link.href = object_url;
                        save_link.download = name;
                        var event = doc.createEvent("MouseEvents");
                        event.initMouseEvent(
                            "click", true, false, view, 0, 0, 0, 0, 0
                            , false, false, false, false, 0, null
                        );
                        save_link.dispatchEvent(event);
                        filesaver.readyState = filesaver.DONE;
                        dispatch_all();
                        return;
                    }
                    // Object and web filesystem URLs have a problem saving in Google Chrome when
                    // viewed in a tab, so I force save with application/octet-stream
                    // http://code.google.com/p/chromium/issues/detail?id=91158
                    if (view.chrome && type && type !== force_saveable_type) {
                        slice = blob.slice || blob.webkitSlice;
                        blob = slice.call(blob, 0, blob.size, force_saveable_type);
                        blob_changed = true;
                    }
                    // Since I can't be sure that the guessed media type will trigger a download
                    // in WebKit, I append .download to the filename.
                    // https://bugs.webkit.org/show_bug.cgi?id=65440
                    if (webkit_req_fs && name !== "download") {
                        name += ".download";
                    }
                    if (type === force_saveable_type || webkit_req_fs) {
                        target_view = view;
                    }
                    if (!req_fs) {
                        fs_error();
                        return;
                    }
                    fs_min_size += blob.size;
                    req_fs(view.TEMPORARY, fs_min_size, abortable(function(fs) {
                        fs.root.getDirectory("saved", create_if_not_found, abortable(function(dir) {
                            var save = function() {
                                dir.getFile(name, create_if_not_found, abortable(function(file) {
                                    file.createWriter(abortable(function(writer) {
                                        writer.onwriteend = function(event) {
                                            target_view.location.href = file.toURL();
                                            deletion_queue.push(file);
                                            filesaver.readyState = filesaver.DONE;
                                            dispatch(filesaver, "writeend", event);
                                        };
                                        writer.onerror = function() {
                                            var error = writer.error;
                                            if (error.code !== error.ABORT_ERR) {
                                                fs_error();
                                            }
                                        };
                                        "writestart progress write abort".split(" ").forEach(function(event) {
                                            writer["on" + event] = filesaver["on" + event];
                                        });
                                        writer.write(blob);
                                        filesaver.abort = function() {
                                            writer.abort();
                                            filesaver.readyState = filesaver.DONE;
                                        };
                                        filesaver.readyState = filesaver.WRITING;
                                    }), fs_error);
                                }), fs_error);
                            };
                            dir.getFile(name, {create: false}, abortable(function(file) {
                                // delete file if it already exists
                                file.remove();
                                save();
                            }), abortable(function(ex) {
                                if (ex.code === ex.NOT_FOUND_ERR) {
                                    save();
                                } else {
                                    fs_error();
                                }
                            }));
                        }), fs_error);
                    }), fs_error);
                }
                , FS_proto = FileSaver.prototype
                , saveAs = function(blob, name) {
                    return new FileSaver(blob, name);
                }
            ;
            FS_proto.abort = function() {
                var filesaver = this;
                filesaver.readyState = filesaver.DONE;
                dispatch(filesaver, "abort");
            };
            FS_proto.readyState = FS_proto.INIT = 0;
            FS_proto.WRITING = 1;
            FS_proto.DONE = 2;

            FS_proto.error =
                FS_proto.onwritestart =
                    FS_proto.onprogress =
                        FS_proto.onwrite =
                            FS_proto.onabort =
                                FS_proto.onerror =
                                    FS_proto.onwriteend =
                                        null;

            view.addEventListener("unload", process_deletion_queue, false);
            saveAs.unload = function() {
                process_deletion_queue();
                view.removeEventListener("unload", process_deletion_queue, false);
            };
            return saveAs;
        }(
            typeof self !== "undefined" && self
            || typeof window !== "undefined" && window
            || this.content
        ));
// `self` is undefined in Firefox for Android content script context
// while `this` is nsIContentFrameMessageManager
// with an attribute `content` that corresponds to the window
    o2.saveAs = saveAs;
    if (typeof module !== "undefined") module.exports = saveAs;

})(this);
